1. Field of the Invention
The present invention relates to a printing apparatus, and more specifically to a printing apparatus provided with a confidential printing function including secure print.
2. Description of the Related Art
For example, a network printer described in U.S. Pat. No. 6,932,523 (corresponding to Japanese Patent Application Laid-open No. 2001-63158) receives a print data from a host apparatus via a network, and then spools the print data in a spool area in a memory (storage section), and adds data sizes of the respective pieces of data in the spool area to calculate the total data size (entire data size) of the pieces of print data. In a case that the total data size exceeds a pre-set reference data size, the network printer reads out a spool-date information included in a print management information and deletes a print data, among the spooled pieces of print data, which has been spooled earliest (oldest spooled data) from the spool area.
According to the network printer described in U.S. Pat. No. 6,932,523, in a case that the total data size of the respective pieces of print data in the spool area exceeds the reference data size, namely in a case that a free space (free capacity) of the spool area becomes less than a certain reference value, the earliest spooled data is deleted from the spool area and the free capacity is increased by an amount corresponding to the size of the deleted earliest spooled data. Note that, however, if the size of a print data which is newly received is small such that the current free capacity of the spool area is sufficient for storing the newly received print data, then there is no need to delete the earliest spooled print data. Nevertheless, the network printer described in U.S. Pat. No. 6,932,523, the earliest spooled print data is deleted. Therefore, in a case that this print data is to be printed again, the print data needs to be transmitted again, which is not suitable for a user.
The present teaching has been made so as to solve the above-mentioned problem, an object of which is to provide a printing apparatus capable of storing received pieces of print data as much as possible and/or as long as possible.